Lego is a brand of plastic toys that provide interlocking modal playsets. they are and have always been pretty expensive. when i was a kid i had a bucket of Legos from several grab bags. the sets themselves are kind of luxury purchases.
that said, this looks pretty dope. like Mario Maker IRL. would be great for younger kids.
heck, it seems like these toys would work independently of the sets (?). so yeah the appeal of a Cat Mario toy that makes sounds and has animations as you play with it irl, that's kinda cool. what's not to understand?